Layer 2 Access Control Lists on EVCs

Last Updated: October 2, 2011

The ability to filter packets in a modular and scalable way is important for both network security and network management. Access Control Lists (ACLs) provide the capability to filter packets at a fine granularity. In Metro Ethernet networks, ACLs are directly applied on Ethernet virtual circuits (EVCs).

Layer 2 Access Control Lists on EVCs is a security feature that allows packet filtering based on MAC addresses. This module describes how to implement ACLs on EVCs.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Layer 2 Access Control Lists on EVCs

Knowledge of how service instances must be configured.

Knowledge of extended MAC ACLs and how they must be configured.

Restrictions for Layer 2 Access Control Lists on EVCs

A maximum of 16 access control entries (ACEs) are allowed for a given ACL.

Only 256 different or unique Layer 2 ACLs can be configured on a line card. (More than 256 ACLs can be configured on a router.)

Layer 2 ACLs function inbound only.

Current Layer 2 ACLs provide Layer 3 filtering options in permit and deny rules. Options that are not relevant to service instances are ignored.

Information About Layer 2 Access Control Lists on EVCs

EVC

An EVC as defined by the Metro Ethernet Forum is a port-level point-to-point or multipoint-to-multipoint Layer 2 circuit. It is an end-to-end representation of a single instance of a Layer 2 service being offered by a provider to a customer. It embodies the different parameters on which the service is being offered. A service instance is the instantiation of an EVC on a given port on a given router.

Ethernet virtual connection services (EVCS) uses EVCs and service instances to provide Layer 2 switched Ethernet services. The EVC status can be used by a customer edge (CE) device either to find an alternative path in to the service provider network or, in some cases, to revert to a backup path over Ethernet or over another alternative service such as Frame Relay or ATM.

For information about the Metro Ethernet Forum standards, see the Standards table in the Additional References section.

Relationship Between ACLs and Ethernet Infrastructure

The following points capture the relationship between ACLs and Ethernet Infrastructure (EI):

ACLs can be directly applied on an EVC using the command-line interface (CLI). An ACL is applied to a service instance, which is the instantiation of an EVC on a given port.

One ACL can be applied to more than one service instance at any time.

One service instance can have one ACL at most applied to it at any time. If a Layer 2 ACL is applied to a service instance that already has a Layer 2 ACL, the new one replaces the old one.

Only named ACLs can be applied to service instances. The command syntax ACLs is retained; the macaccess-listextended command is used to create an ACL.

The showethernetserviceinstance command can be used to provide details about ACLs on service instances.

MIBs

RFCs

RFC

Title

No new or modified RFCs are supported by this release.

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Feature Information for Layer 2 Access Control Lists on EVCs

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 2

Feature Information for Layer 2 Access Control Lists on EVCs

Feature Name

Releases

Feature Information

Layer 2 Access Control Lists on EVCs

12.2(33)SRD 15.0(1)S

The Layer 2 Access Control Lists on EVCs feature introduces ACLs on EVCs.

The following commands were introduced or modified: interface,macaccess-groupin, macaccess-listextended,showethernetserviceinstance.

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